Nuclear Power in your car

Rui Lin Tan

NPRE 498 – Energy Storage

(Radioisotopic Thermoelectric Generators)

Scope

• Background

• How it works

• Current Applications

• Advantages/ Disadvantages

• Possible Improvements

• RTG vehicle?

Background – Nuclear Batteries

– Thermocouple type (Radioisotopic Thermoelectric Generators)

Background – RTGs

• First developed in the US in the 1950s by Mound Laboratories in Ohio

• Initially developed under the general designation: Systems for Nuclear Auxiliary Power (SNAP)

• First used in 1961 as SNAP 3 to power a navy spacecraft.

– Weight: 4lbs, Power: 2.5W, Life: 280 days

• First Terrestrial use in “Fairway Rock” Alaska in 1966 (-1995)

How it works

• Energy Storage Medium: Radioisotopic Material capable of producing heat

• Direct conversion of heat to electricity

– Seebeck Effect

How it works

• Criterion for selection of Isotopes

– 100 days < Half-Life < 100 years

– No gamma emission

– Power > 0.1 W(th)/g

Radioisotope Heater Unit

Current Applications

• Power Source in space

• Power for remote facilities/ equipment

Curiosity Rover Unmanned Buoy

Advantages

• Long Lifetime of continuous power

• Minimal maintenance needed (No moving parts)

• Small size and weight

• Independent of any external input

• Safety (No parts prone to failure)

Disadvantages

• Low Efficiency (<10%)

• Radioisotope decay ( ~0.7-0.8% power loss per year)

• Safety

– Radioactive Contamination

– Proliferation

Possible Improvements

• Stirling Engine

– 4x efficiency over pure RTGs

Current Battery Powered Vehicle

Tesla Model S • Power output: 270kW / 362 hp • Battery Capacity: 85 kWh • Range: ≈ 300 miles

• 4 hp (3kW) Car! -> Max Speed: 22 mph

• Range: However far you can drive in 3 years at 22 mph! (578160 miles)

RTG powered vehicle

Other Possible Terrestrial Uses

Nissan Leaf

Chevy Volt

Porsche 918

Ford Focus EV

Tesla S

Toyota RAV4 EV

y = 3.053x

0

50

100

150

200

250

300

0 10 20 30 40 50 60 70 80 90

Ran

ge (

mile

s)

Battery Capacity (kWh)

Battery Capacity vs. Range

1 kWh → 3.053miles range!!

For 1462.2 Wth, we need:

2.611kg of Pu-238

• At $4000/g, 2.611kg of Pu will cost:

$10.44 million!

• Proliferation Issues, etc.

Directions for advancement

• Another Radioisotope which produces MORE POWER / GRAM than Pu-238, but which requires LESS SHIELDING

• More efficient way to convert heat to electricity inside of a small space constraint

Every great advance in science has issued from a new audacity of imagination.

~John Dewey, The Quest for Certainty, 1929

No one should approach the temple of science with the soul of a money changer.

~Thomas Browne

References

• NUCLEAR BATTERY-THERMOCOUPLE TYPE SUMMARY REPORT. http://www.osti.gov/bridge/purl.cover.jsp?purl=/4807049-6bvOmJ/4807049.pdf

• http://www.spaceflightnow.com/atlas/av028/111117mmrtg/ • http://www.animatedsoftware.com/cassini/jpltruer.htm • Anres Najar, "Electric Vehicle Conversion". NPRE 498 Research Presentation, Fall

2011 • NPRE 402, “Radioisotopes Power Production”. Professor M. Ragheb

https://netfiles.uiuc.edu/mragheb/www/NPRE%20402%20ME%20405%20Nuclear%20Power%20Engineering/Radioisotopes%20Power%20Production.pdf

• “Radioisotopic Battery with Vacuum Electrical Insulation”. J. R. Lee, G. H. Miley, N. Luo, M. Ragheb. 2007.

• "Plutonium." Chemicool Periodic Table. Chemicool.com. 08 Oct. 2012. Web. 11/5/2012 <http://www.chemicool.com/elements/plutonium.html>.

• “Space Radioisotope Power Systems: Advanced Stirling Radioisotope Generator” NASA. Jan 2011. <http://www.ne.doe.gov/pdfFiles/factSheets/SpaceRadioisotopePowerSystemsASRG.pdf>.

Questions?